<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>标签规范</title>
<style>
	#box1{ width : 100px; height : 100px; background : red; }
	#box1 a{ display : block; width : 100%; height : 100%; }
</style>
</head>
<body>
<div id="box1">
     <a href="#"></a>
 </div>
</body>
</html>
